Process for extracting oleaginous and other materials with volatile solvents



Feb. l0, 1931.

J SAVAGE PROCESS FOR EXTRACTING OLEAGINOUS AND OTHER MATERIALS WITHVOLATILE SOLVENTS 1927 3 Sheets-Sheet l Filed oct. 1B

5 Sheets-Sheet 2 Filed Oct. 18 1927 MATERIALS WITH VOLATILE SOLVENTSFIR.

J SAVAGE PROCESS FOR EXTRACTING OLEAGINOUS AND OTHER S- III Feb. l0,1931.

Feb. 10, 1931. J. SAVAGE 1,791,906

PROCESS FOR EXTRACTING OLEAGINOUS AND OTHER MATERIALS WITH VOLATILESOLVENTS Filed Oct. 18, 1927 3 Sheets-Sheet 5 Patented Feb. 10, 1931UNITED STATES PATENT OFFICE Josarnsavaen, or mmcon'n, ENGLAND PROCESSFOB EXTRAC'TING OLIAGINOUS AND 0TEEB-IATEBIALS WITH 'VOLATILE BOLVENTSApplication :tiled October 18, 1927, Serial No. 227,039, and in GreatBritainootober 22, 1926.

Part of the subject matter of the present invention was disclosed in myco-pendmg application Serial No. 155,324 from which it has beentransferred to the present application.

The invention relates to an improved proceffect economy in the heatrequired for the `volatilization of the solvent and to shorten the timerequired for extraction. The scope of the invention is defined in theVappended claims.

Two forms of apparatus with which the process of the present inventionmay be carried out are illustrated in the accompanying drawings, whereinFigure l shows a sectional elevation of "one form ,of the apparatus.

Figure 2 shows a modified construction usingan external condenser.

Figures 3, 4 and 5 show enlarged views of the automatic water separatorin side elevation, plan, and end elevation respectively.

A closed container 1 in which a volatile solvent may bevolatilized has aperforated platform 2 supported on suitable brackets 3, which dividesthe container into upper and 5 inside of the vessel 1 and a lip on thetray lower chambers A and\B respectively. The.

aby the -valve 34. After the removal of the overhangs the cup. A pipe'16 through which condensed liquid collected on the tray flows down tothe water separator 17 and the automatic water release 18, passesthrough the wall of the container l into the cup 13. Solvent is returnedto the chamber B by the pipe 19, while a draining valve 21 may beprovided.

The charge of material is introduced through the opening' 22 and whenextracted 60 is removed through 23.

In order to provide a sprinkling effect over the material an additionalcoil 24 is provided below the tray. Solvent vapour condenses on thiscoil and then drops back on 55 to the material giving a sprinklingeffect. The tray 14 ma, be'made in two semi-circular halves, whic can beintroduced through the man-hole 23.

Referring to Fig. 2 a pipe 25 leads the hot vapours of solvent andextracted water to an external condenser 26. Inlet and outlet pipes forthe condenser cooling medium are shown at 27 and 28. The condensedsolvent and water all by the pipe 29 to a water separator 30 includingan automatic ball release valve arranged to separate the condensedsolvent and water. A sight glass 33 may be provided in the waterseparator if desired. The solvent is returned to the chamber B by thepipe 31. A pressure gauge 32 may also be provided.

In operation, a charge of the material to be extracted is placed in theupper chamber A and a volatile solvent contained in B is vapourized bythe heating coil 4. The vapour passes through the perforate partition 2and penetrates to the material. The water present in the material isremoved by the vapour of the solvent and the mixed vapours of wanter andsolvent rise to the top of the apparatus, where they pass through thepipe 25 to the external condenser 26,7and the liquid falls directly intothe separator 30.

The hot solvent and water are separated at the highest possibletemperature consistent with effective separation. The amount andtemperature of the cooling fluid circulating the condenser is capable ofregulation Water from the charge, the oil is removed by the solvent andthe solution of oil in solvent is removed as desired and distilled inany known manner to isolate the oil and recover the solvent.

The process is extremely simple and edicient. The solvent circulatescontinuously in a, single closed cycle under substantially the samepressure in all parts of the cycle and considerable economy of heat iseffected by returning the solvent in a nearly boiling condition to theextraction chamber. The working conditions are arranged so that thetemperature of the extracting medium never falls more than a few degreesbelow its boiling point under the pressure existing in the apparatus,and consequently the heat lost by condensation is reduced to a minimum.Hence the amount of heat which has to be supplied for revolatilizationis small, and the thermal efficiency of the process is correspondinglyhigh.

The action of the automatic water separator 17 (F ig.1) or 30 (Fig.2) isas follows. The Water is released by the movement of a float 35 (Fig. 5)contained in a chamber wherein the pressure is substantially the same asthe working pressure in the extraction chamber. The float 35 actuates aspring loaded needle valve 36, which is arranged so that the water isautomatically run oli` when more than a certain minimum quantity hascollected in the chamber. The invention is not restricted to solventsheavier than water (e. g. trichlorethylene) but can be used withsolvents lighter than water (e. g. benzene) by a slight modification ofthe release valve.

The water and solvent levels may be observed through the sight glasses33. If the rormal level of the heavy solvent is below the lower edge ofthe opening 37 it is desirable to provide a solvent drain pipe 38 asshown, to drain the float chamber of solvent.

The normal solvent level is just below the platform 2 and the positionof the separator in relation to this level is so arranged that theseparation and stratification of the liquids takes place in and aboutthe space 39, and can be Watched through the sight glasses. Inoperation, owing to the slight drop of pressure through the condenser 26the level of the liquids in the separator is slightly above the level inthe volatilization chamber, permitting separation to occur in the regionof the float-actuated valve.

The process is usually carried out at a pressure of from 10 to 25 lbs.per square inch above atmospheric pressure. l/Vhen treating bones orother organic materials the pressure should not be too high or it ispossible that the materials will char.

As the separation takes place at the pressure existing in the apparatus,a pump to return the separated solvent to the volatilization chamber isrendered unnecessary.

If desired, electrical or other methods of heating may be used tovolatilize the solvent.

I declare that what I claim is 1. A process for extracting oleaginousmaterials containing aqueous moisture with a water insoluble liquidvolatile hydrocarbon solvents which comprises performing the followingoperations in a closed circuit under pressures substantially greaterthan atmospheric: volatilizing said volatile solvent in the base of anextraction chamber, passing the vapours through said material,condensing said vapours to a limited extent consistent with effectiveseparation of water and solvent, automatically separating said water,and returning said separated solvent direct to said extraction chamberfor rc-volatilization at a temperature just below its boiling point atthe pressure existing in said circuit.

2. A process of extracting moist oleaginous materials with waterinsoluble liquid volatile hydrocarbon solvents consisting in distillinga volatile solvent in a closed circuit under pressure substantiallygreater than atmospheric through the material to be extracted,condensing the vapours by external means, separating the extracted waterPutomatically and returning hot separated solvent for re-distillation attemperature near the boiling point of said solvent at the pressureexisting in said circuit. I

3. A process of extracting moist oleaginous materials withWater-insoluble, liquid, volatile hydrocarbon solvents which comprisescirculating said solvent in a closed circuit through an extractionchamber, said solvent passing as vapour through said extraction chamber,under pressure substantially greater than atmospheric, condensing saidvapours, automatically separating the extracted water, and returninghot, separated solventto the circuit at a. temperature near the boilingpoint of said solvent at the pressure existing in said circuit.

4. A process of extracting moist olea ginous materials withwater-insoluble, liquid, volatile hydrocarbon solvents which comprisesvapourizing said solvent, passing the vapours through said materialunder superatmospheric pressure, condensing said vapour, automaticallyseparating the extracted moisture, and returning separated solvent forrevapourization at a temperature just below the boiling point of saidsolvent at the existing pressure, the solvent circulating in acontinuous closed circuit.

5. A process of extracting moist oleaginous materials withwater-insoluble liquid volatile hydrocarbon solvents which comprisesvolatilizing the solvent in the base of a container, passing said vapourthrough the mai from water in an automatic water separator, andreturning separated solvent for re-volatilization at a temperature verynear to the boiling point of said solvent at the pressure existing insaid container, all the above operations being performed in a closedcircuit.

6. A process for extracting oleaginous materials containing aqueousmoisture with Water-insoluble liquid volatile hydrocarbon solventsoperating continuously in a closed circuit which comprises vapourlzingsaid solvent, circulating the vapours through said material underpressure substantially higher than atmospheric, condensing said vapours,automatically separating sald solvent and Water'in a Waterseparator'exposed to the pressure in said circuit, and returningseparated solvent direct for re-vapourizatlon at a temperature justbelow the boiling point of said solvent at the pressure existing in saidcircuit.

7. A process of extracting moist oleaginous materials with Waterinsoluble liquid volatile hydrocarbon solvents which comprisesvolatilizing a solvent under super-atmospheric pressure, passing thevapours through said material, condensing the vapours to a limitedextent in an external condenser, automatically separating said solventand water, and returning nearly boiling solvent direct forre-volatilization.

8. A process of extracting moist oleaginous materials with Waterinsoluble volatile hydrocarbon solvents which comprises volatilizing thesolvent in the base of a container, passing the vapours through thematerial under superatmospheric pressure, condensing said vapours in anexternal condenser, separating said solvent and water automatically in aseparating chamber exposed to the pressure of said vapours, releasingsaid water from said separating chamber, and returning nearl boillngseparated solvent to the base o said contamer for revolatilization.

In witness whereof, I have hereunto signed my name this 7th da ofOctober 1927.

.l1 OSEPH SAVAGE.

